Motorcycle is sputtering, what's going on?

I've had in the shop twice with a carb clean, since cleaning them 3 times by myself didn't work. Each time I pick it up from the shop, it runs great for a week or 2. No vacuum leaks that I can find, runs same without air filter. I ordered a fuel filter which I don't have now. Anything else?
2000 Honda Nighthawk 750

Clean the carb again, fuel filter, spark plug, coil or rectifier may need to replaced. Take a look in the cylinder via spark plug hole. If it is very black(lots of carbon build up) then you may need to take head off and inspect. The valves may be leaking.

Carbs contain components made from soft metal (brass and alloys) these do wear out, sometimes cleaning will not help.

But air supply can affect the fuelling too.

Do a compression check if you want to know if the valves are leaking - the piston will probably be black if it is running too rich - but not likely to hurt the valve seats.

So you need to find out if it is running lean or rich. Put a fresh set of plugs in, take it out on a deserted (very low traffic area) and get the bike up to sputtering speed and hold it there as long as you can. Hit the kill switch, grab the clutch coast to the side of the road and do a plug reading. Then trouble shoot from your finding (too rich, too lean, just right).

Look in the gas tank.
If you see any rust on the walls of the tank, or any foreign debris floating around, that junk is re-clogging the carbs every time you clean them.
Clean the carbs again and install a fuel filter before running the engine.

Ok, the carbs have been cleaned 5 times, time to look elsewhere. Like Jim said, check the tank for rust/crud. Also, it might be bad fuel from wherever you buy it from (unlikely but possible). Try somewhere else.